LCD panels are widely used in flat panel displays and are gaining increasing popularity over cathode ray tube (CRT) or LED panels because of their various advantages such as light weight, high resolution, and low power consumption. Known LCD panels are typically of the reflective or transmissive types. The reflective type LCD uses reflection to illuminate the LCD panel and its operation is dependent on the availability of external light sources. The transmissive type LCD uses an internal light source for illumination and the internal light source is commonly referred to as backlight. An advantage of the transmissive type LCD, which is also commonly referred to as backlit LCD, is its usefulness for outdoor operation because its backlight intensity can be adjusted according to the ambient light conditions of the outdoor environment which changes widely during different times of the day and according to weather conditions.
Although a backlit LCD display is an appropriate candidate for outdoor use, the harsh outdoor operating conditions could be adverse to the operation of an LCD display. For example, when an LCD panel is exposed directly under sunlight, the surface temperature of the LCD cells can rise to above 80° C., and prolonged exposure to such high temperatures could result in premature darkening of an LCD screen, resulting in premature failure of the LCD panel. Another challenge which needs to be tacked to enable backlit LCD to be commercially meaningful as an outdoor image display is the need to provide sufficient backlight to provide adequate contrast for the viewing public. However, additional backlight would lead to additional heating of the apparatus which is not compatible with preferred operating conditions of LSD. On the other hand, when the outdoor conditions become extremely cold, an LCD display would not function properly.
Therefore, it would be advantageous if there could be provided improved LCD apparatus which alleviate shortcomings of conventional LCD apparatus.